1. Field of the Invention
The present invention relates to a valve unit and methods for fastening a valve unit to a base.
2. Statement of the Problem
A valve island is a grouping of multiple valves that are used to meter and/or control the flow of fluids. The fluids can include liquids and gases. A valve island is commonly used to provide and control multiple fluid streams to a common device or for a common purpose. For example, in the pharmaceutical industry, multiple valves may be used to meter out compounds that are mixed in order to form a final compound. Another use of a valve island is in metering fluids in biotech applications. Yet another use is a valve island for controlling the delivery of pressurized gases in an industrial setting.
A valve island comprises a base that provides common installation/affixing features. The valves of a valve island are grouped together on this base. The individual valve units of the valve island can be added and removed as desired and the numbers of valves can be selected and changed. In addition, valves of different types or having different operating characteristics can be selected and installed on the valve-island.
In the prior art, a valve unit is often affixed to a base by fasteners, such as machine screws, for example. Such a prior art fastener is typically located at the sides of the valve unit, and compresses the valve unit onto the base. A fastener located in between multiple valves of a valve grouping holds a valve on each side of it, and therefore cannot flex, move, or bend. However, in the prior art, a fastener on a side of a valve unit that does not contact or abut another valve unit is free to move away from the valve unit in question. Consequently, the fastener can move or flex away from the valve unit. In some circumstances, the fastener can bend or otherwise deform. This leads to improper seating of the valve unit on the valve island.